Carbon-isotope stratigraphy of the East Isthmus Bay (Port au Port and St. George groups) and Broom Point (Cow Head Group) sections, western Newfoundland, Canada

• Main Author: Scorrer, Sebastian
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2018
• Subjects: Berry Head; Broom Point; Canada; Cow Head; Green Point; Shallow Bay; Watts Bight; Newfoundland
• Online Access: https://research.library.mun.ca/13361/; https://research.library.mun.ca/13361/1/Scorrer_Sebastian_MSc.pdf

The carbon-isotope stratigraphy of two carbonate sections spanning the Upper Cambrian to lowermost Ordovician from western Newfoundland were investigated for their potential for regional and global correlation with coeval carbonate sections. The East Isthmus Bay (EI) section consists of carbonates from the uppermost Cambrian (Furongian) Berry Head Formation (~ 160 metres thick), and the lowermost Ordovician (Tremadocian) Watts Bight Formation (~ 30 metres thick) that accumulated in a shallow-marine setting on the Laurentian platform/passive margin in western Newfoundland, Canada. Petrographic investigation shows that the sampled carbonates have retained at least their near-primary sedimentary fabrics, though there is minor recrystallisation in the lower section. The Broom Point (BP) section encompasses the Broom Point North (~ 20 metres sampled) and Broom Point South (~ 120 metres sampled) sections. The sections cover the Shallow Bay (Furongian) and Green Point (Tremadocian) formations, these carbonates formed further down the slope in slightly deeper water. Petrographic examination of the carbonates implies the retention of near-primary sedimentary fabrics. Correlation between the Sr and Mn concentrations of carbonates from both sections suggests the Broom Point carbonates have been more impacted by diagenesis than their East Isthmus Bay counterparts due to the higher correlation (R²BP = 0.4, R²EI = 0.18, respectively). The East Isthmus Bay δ¹³C values show insignificant correlation with their Sr (R²EI = 0.04), Mn (R²EI = 0.001), and Fe (R²EI = 0.02) counterparts, implying preservation of at least near-primary carbon-isotope compositions. On the other hand, the Broom Point section shows considerable correlation of Sr and Mn with their δ¹³C counterparts (R²BP = 0.54 and R²BP = 0.29, respectively), implying considerable alteration of the primary geochemical signatures. Though a poor correlation is seen between δ¹³C and Fe (R²BP = 0.14) in the Broom Point carbonates and insignificant correlation is seen between ...